Pressure regulator

ABSTRACT

A variable device for regulating the outlet pressure of a fluid from a valve body, includes a pressure-sensing chamber having a wall formed by a resilient self-restoring diaphragm which is responsive to pressure in the chamber. A valve element connected to the diaphragm controls flow into the chamber. Increased pressure in the chamber decreases the flow into the chamber and decreasing pressure increases flow whereby fluid flow out from the chamber is maintained at a desired pressure. The outlet pressure is adjusted by deflecting the diaphragm in a direction to open the valve while permitting a section of the diaphragm connected to the valve member to remain responsive to the pressure in the chamber. An adjustment cover is provided to adjustably deflect the diaphragm and includes a catch mechanism to allow adjustment of the fluid outlet pressures and also retain the device at a desired value. An indicator arrangement may be provided to visually indicate the fluid outlet pressure.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/931,385, filed Aug. 14, 2001, now U.S. Pat. No. 6,619,308 which is acontinuation-in-part of U.S. patent application Ser. No. 09/350,955,filed Jul. 9, 1999, now U.S. Pat. No. 6,273,117.

FIELD OF THE INVENTION

This invention relates to fluid pressure regulators, and particularly toregulators well suited for controlling the output pressure ofelastomeric balloon or mechanical pumps. More specifically, the presentinvention relates to a variable fluid pressure regulator which allowsfor convenient adjustment of fluid outlet pressure.

BACKGROUND OF THE INVENTION

Pressure regulators that reduce or cut off inlet flow of a fluid whenthe outlet pressure starts to exceed a predetermined maximum and thatopen or increase flow when the outlet pressure has been sufficientlyreduced are well known in the art. Such regulators generally include acoil spring that biases a valve member open, and a pressure-sensingelement responsive to excess inlet pressure which closes the valvemember. In this arrangement, increasing liquid pressure compresses thespring to force the valve member towards a valve seat. As the valvemember approaches the valve seat, liquid flow through the regulatorbecomes more restricted. When the defined pressure level is reached,further flow restriction is stopped, or the valve member contacts thevalve seat to cut off flow. When the output pressure drops below thedefined pressure, the valve member moves away from the valve seat andflow increases. This cycle is rapidly repeated over and over to maintainthe output pressure at the desired setting.

Numerous pressure regulating devices teach the use of a coil spring,such as U.S. Pat. No. 3,412,650 by Stang, U.S. Pat. No. 3,547,427 byKelly, U.S. Pat. No. 3,603,214 by Murrell, U.S. Pat. No. 3,747,629 byBauman, U.S. Pat. No. 3,825,029 by Genbauffe, U.S. Pat. 4,074,694 byLee, U.S. Pat. No. 4,621,658 by Buezis et al., U.S. Pat. No. 4,744,387by Otteman, U.S. Pat. No. 5,141,022 by Black, and U.S. Pat. No.5,732,736 by Ollivier. However, a need exists for a pressure regulatordevice without a spring coil, thereby resulting in a more reliabledevice with fewer parts which is easier to assemble and costs less.

The majority of the subject pressure regulators of the above-referencedpatents are manufactured to provide a single, specific fluid outletpressure or be adjustable between a high and a low setting. However,there also exists a need for a variable pressure regulator device thatallows for the selection, from a range of values, of a desired fluidoutlet pressure by a user. This capability is particularly desirable inconnection with small pumps used in the medical field wherein fluids arebeing dispensed to a patient.

SUMMARY OF THE INVENTION

A goal of preferred embodiments is to provide a simplified pressureregulator having fewer parts thereby making it easier to assemble, lessexpensive and less likely to break. Instead of having the traditionalsprings located above and below a flexible diaphragm, a resilientdiaphragm is employed that by itself controls input flow and regulatesoutput pressure. The diaphragm is made of an elasticomeric material, andis designed not only to act as a diaphragm, but also to replace thepressure sensing spring and the valve seat spring.

Preferably, the diaphragm is manufactured to be flat, however, afterinstallation into the regulator, an adjuster is moved to deflect thediaphragm. The amount of deflection corresponds with the desired outletfluid pressure. The diaphragm resists deflection when outlet pressure isless than the desired level, but flexes towards a closed position whenthe outlet pressure exceeds this level. Thus, this diaphragm uniquelyhas the additional advantage of functioning as a spring without havingany of the disadvantages.

Additionally, a preferred embodiment of the fluid pressure regulatorincludes a cover, which engages the adjuster such that rotation of thecover results in rotation of the adjuster to deflect the diaphragm andadjust the fluid outlet pressure, as described above. Such aconstruction advantageously allows convenient adjustment of the fluidoutlet pressure by medical personnel and, thus, permits the variablefluid regulator to accommodate a variety of fluid dispensing needs.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the present invention will be betterunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawing wherein:

FIG. 1 is a cross-sectional view of a preferred embodiment of a pressureregulator;

FIG. 2 is a cross-sectional view of an additional embodiment of apressure regulator;

FIG. 3 is an exploded, perspective view of the pressure regulator ofFIG. 2 as viewed from above;

FIG. 4 is an exploded, perspective view of the pressure regulator ofFIG. 2 as viewed from below;

FIG. 5 is a cross-sectional view of another embodiment of a pressureregulator;

FIG. 6 is an exploded, perspective view of the pressure regulator ofFIG. 5 as viewed from above;

FIG. 7 is an exploded, perspective view of the pressure regulator ofFIG. 5 as viewed from below.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, the pre-set pressure regulator, indicatedgenerally by the numeral 10, comprises a base 15, a resilient wall ordiaphragm 20, a retainer 25, and an initial adjuster in the form of acap 30. The base 15 has an inlet 35 where fluid is introduced into theregulator 10 and an outlet 40 where the fluid exits at the desiredpressure. A central, axial passage 45 extends through the base 15, andis in fluid communication with the inlet 35. The diameter of the openend at the top of the passage 45 which is smaller than the lower portionforms a valve seat 50. A plug 55 closes the lower end of the passage.

The top surface of the base 15 is concave and forms the lower boundaryof a fluid pressure-sensing chamber 60. The perimeter of the top surfaceof the base member has an angled, annular shoulder 65 which defines aseating and gripping surface for the diaphragm 20. The shoulder 65 hasan externally threaded lip 70 which mates with interior threads on theretainer 25, which is generally ring shaped. The outlet conduit 40 influid communication with the chamber 60 extends from the top surface ofthe base 15 to an exterior surface of the base 15.

The diaphragm 20 is a generally circular, preferably generally flatmember which has an outer annular portion clamped between the baseshoulder 65 and a flat annular surface 90 on the retainer 25 to sealthat area. This causes the bottom surface of the diaphragm to form theupper boundary of the pressure-sensing chamber 60. The diaphragm ispreferably made of an elastomeric material, such as silicone so that itwill be responsive to fluid pressure changes in the chamber 60 and has asignificant “memory” so that it is self-restoring. Depending from thediaphragm 20 is an integral valve stem 75 which extends axially throughthe chamber 60 and into the passage 45. A valve element 80 on the lowerend of the valve stem is positioned in the passage 45 to cooperate withthe valve seat 50. The valve element is preferably ball-shaped asillustrated, but may be in the form of a disk or other suitable shapethat will properly mate with the valve seat. During assembly, the valveelement 80 may be lubricated with alcohol to enable it to be pushedthrough the valve seat into the passage 45.

The retainer 25 may be ultrasonically welded to the base 15 if desired.An annular area 95 of the retainer 25 slopes upwardly, and inwardly toan interiorly threaded collar 105, which is part of the retainer. Theadjuster cap 30 has a flat upper wall 110 and a cylindrical flange 115extending downward into the collar 105. The exterior surface of theflange 115 is threaded to mate with the threads of the collar 105. Thecap 30 is adjusted so that its lower annular end contacts the topsurface of the diaphragm 20. The circular, central section of thediaphragm, which is bounded by the cylindrical flange 120, is responsiveto fluid pressure in the chamber 60. The loading by the adjusting cap 30pushes the diaphragm 20 downward, thereby unseating the valve element80, as shown in the drawing. The adjuster may also be in sliding orcam-like engagement with the retainer.

The upper surface of the diaphragm 20 and the initial adjusting cap 30form an upper interior space 130 that is separated from thepressure-sensing chamber 60 by the diaphragm 20. Vents 125 extendthrough the flat surface 110 of the adjusting cap 30 to prevent pressurebuild-up in the upper interior space 130, and to facilitate turning theadjuster cap 30 when setting the desired pressure.

The base 15, plug 55, adjusting cap 30, and retainer 25 are preferablymade of polyvinyl chloride, but may be made of other durable,inexpensive materials known to those of ordinary skill in the art.

When the diaphragm 20 is assembled within the pressure regulator 10,between the angled shoulder 65 of the base 15 and the flat surface 90 ofthe retainer 25, the valve member 80 is seated in a sealed closedposition. After a pressure source is attached to the inlet 35, the cap30 is advanced against the diaphragm causing the annular tip of the capflange 115 to deflect the diaphragm 20, thereby unseating the valveelement 80 from the valve seat 50. While the valve element 80 isunseated, fluid travels through the inlet 35 and the valve seat 50,flows into the fluid sensing chamber 60, and out through outlet 40. Thecap is adjusted until the desired outlet pressure is attained. For apreset pressure device, a suitable adhesive or the like is applied tothe threads at 115 to prevent changes in the output pressure setting.

When the pressure of the fluid in the chamber 60 exerts a force againstthe bottom of the diaphragm 20 greater than the desired value initiallyset by the adjusting cap 30, a force imbalance occurs. The force of thefluid in the chamber 60 pushes the resilient central section of thediaphragm 20 upward causing the valve member 80 to move in aflow-reducing or flow stopping direction towards the valve seat 50. Whenthe outlet pressure drops below the desired level, the resilientdiaphragm central section moves the valve member 80 away from the valveseat 50 and fluid flow into the chamber 60 increases. The resiliency ofdiaphragm 20 provides its central section the self-restoring flexibilityto respond to the pressure of the fluid in the fluid pressure-sensingchamber 60. Consequently, diaphragm 20 is an active member responsive topressure changes without the need for a conventional spring.

The valve stem and the valve may be made of the same material as thediaphragm 20 and the valve member 80, and may be made as a one pieceunit. However, a valve stem 75 made from a material stiffer than thatused to make the diaphragm 20 is better able to maintain a constantpressure over a wider range of input pressures. To increase stiffnessand obtain this improved effect, a rigid pin (not shown) may be insertedinto the valve stem 75, after the diaphragm 20 is assembled into thevalve body but before the adjusting cap 30 is installed. Alternatively,the cross section of the valve stem 75 may be increased over part or allof its length to increase stiffness. Further, the valve stem may be acompletely separate part that links a separate valve element to thediaphragm.

The pressure regulator is useful in many applications but isparticularly suited to control the output pressure of elastomericballoon or other mechanical pumps.

FIGS. 2-4 illustrate an additional embodiment of a fluid pressureregulator, indicated generally by the reference numeral 10′. Thepressure regulator 10′ is similar in construction and function to thepressure regulator 10 of FIG. 1. Accordingly, like reference numeralswill be used to denote like components, except that a (′) will be added.

With similarity to the embodiment of FIG. 1, pressure regulator 10′comprises a valve body including a base 15′ and a retainer 25′, aresilient wall or diaphragm 20′, and an adjuster in the form of a cap30′. The base 15′ has an inlet 35′ where fluid is introduced into theregulator 10′ and an outlet 40′ where the fluid exits at the desiredpressure. A central, axial passage 45′ extends through the base 15′, andis in fluid communication with the inlet 35′. The diameter of the openend at the top of the passage 45′, which is smaller than the lowerportion, forms a valve 50′. A plug 55′ closes the lower end of thepassage.

As with the embodiment of FIG. 1, the diaphragm 20′ of the presentpressure regulator 10′ is clamped between the base 15′ and the retainer25′. Therefore, the bottom surface of the diaphragm 20′ forms the upperboundary of the pressure sensing chamber 60′. An upper surface of thebase 15′ forms the lower boundary of the pressure sensing chamber 60′.Depending from the diaphragm 20′ is an integral valve stem 75′, whichextends axially through the chamber 60′ and into the passage 45′. Avalve element 80′ on the lower end of the valve stem is positioned inthe passage 45′ to cooperate with the valve seat 50′.

As in the embodiment of FIG. 1, the adjuster cap 30′ of the presentpressure regulator 10′ is threadably engaged within a central portion ofthe retainer 25′. The adjuster 30′ may be advanced or retracted relativeto the retainer 25′ such that a lower annular end 120′ contacts the topsurface of the diaphragm 20′. Advancing or retracting the adjuster 30′alters the force necessary to close the valve element 80′ against thevalve seat 50′, thereby adjusting the fluid outlet pressure of thepressure regulator 10′, as described above with respect to theembodiment of FIG. 1.

The pressure regulator 10′ of FIGS. 2-4 additionally comprises a cover150. Preferably, the cover 150 is rotatably supported on the retainer25′ and engages the adjuster 30′ such that the adjuster 30′ is fixed forrotation therewith. Thus, rotation of the cover 150 results incorresponding rotation of the adjuster 30′ such that the deflection ofthe diaphragm 20′ is altered, thereby adjusting the fluid outletpressure.

With reference to FIGS. 3 and 4, the cover 150 preferably includes aplurality of flexible lock tabs 152. The lock tabs 152 engage theretainer 25′ to hold the cover 150 in a substantially fixed axialrelationship with the retainer 25′, while allowing rotation with respectthereto.

Each lock tab 152 includes a substantially transversely extending locksurface 154 configured to engage a retaining surface 156 of the retainer25′. The retaining surface 156 may be a transversely extendinguninterrupted annular surface. However, the retaining surface 156 mayalso include a series of interrupted surfaces, preferably with theinterruptions being less than a width of any one of the flexible locktabs 152.

The illustrated pressure regulator 10′ includes four, equally spacedlock tabs 152 (FIG. 4), however, a lesser or greater number of lock tabs156 may be used. Advantageously, the lock tabs 152 and retaining surface156 construction allow assembly of the cover 150 to the retainer 25′without the use of tools or additional fasteners. However, othersuitable coupling methods may also be used.

With reference to FIG. 2, the cover 150 includes a pair of downwardlyextending shafts or pins 157 which engage vent holes 125′ of theadjuster cap 30′. The shafts 157 may be of a smaller diameter than thatof the vent holes 125′ such that pressure build-up in the upper chamber130′ is avoided.

The pair of shafts 157 fix the adjuster cap 30′ for rotation with thecover 150, while simultaneously allowing the adjuster cap 30′ to moveaxially with respect to the cover 150 by sliding on the shafts 157.Thus, when the cover 150 is rotated, the adjuster cap 30′ both rotates,due to its engagement with the cover 150 via the shafts 157, and movesaxially with respect to the cover 150, due to its threaded engagementwith the retainer 25′.

The pressure regulator 10′ also includes a catch, or detent, mechanism158 arrangement for locating the cover 150 in a desired angular positionwith respect to the retainer 25′. Each of a plurality of recesses 160define a plurality of angular positions relative to the base 15′. Thecover 150 includes a depending flexible tab 162 adjacent the coverperiphery. The tab 162 includes an inwardly extending projection 164(FIG. 4). The illustrated projection 164 is hemispherical in shape andeach of the recesses 160 are substantially semi-cylindrical in shape.However, othersuitable mating shapes may also be used, as can bedetermined by one of skill in the art.

With reference to FIG. 2, the catch mechanism 158 is constructed suchthat the projection 164 is biased into engagement with a recess 160 bythe inherent biasing force of the flexible tab 162. As a result, thecover 150 and thus the adjuster cap 30′ are held in one of the annularpositions defined by the plurality of recesses 160. When the cover 150is rotated relative to the base 15′ with a sufficient force, theprojection 164 is disengaged from its current recess 160 and moves intoengagement with the next adjacent recess 160 in the direction ofrotation of the cap 150. Preferably, the inherent biasing force of theflexible tab 162 is such that a caregiver and/or patient may rotate thecover 150 by hand, while also inhibiting undesired rotation of the cover150 due to vibrations or inadvertent contact.

Advantageously, with such a construction, rotation of the cover 150results in rotation of the adjuster cap 30′ which, in turn, alters thedeflection of the flexible diaphragm member 20′. As discussed above, theoutlet fluid pressure is influenced by the deflection of the flexiblediaphragm member 20′. Accordingly, the pressure regulator 10′ allows acaregiver and/or patient to easily adjust the fluid outlet pressure to adesired value.

With reference to FIG. 3, the fluid pressure regulator 10′ includes anindicator arrangement 166, which correlates the angular position of thecover 150 with a resulting fluid outlet pressure. Advantageously, withsuch a construction the caregiver is able to adjust the variablepressure regulator 10′ to a proper outlet pressure for a specific fluidbeing dispensed.

The illustrated indicator arrangement 166 comprises an annular scale 168on the retainer 25′. A reference indicia 170 is provided on the cap 150and, when the cap 150 is assembled to the retainer 25′, is aligned suchthat at least a portion of the scale 168 is indicated by the referenceindicia 170. In the illustrated embodiment, the reference indicia 170comprises a window 172 and an arrow 174. The window 172 is sized andshaped preferably to display one demarcation of the scale 168. The arrow174 allows for rapid identification of the location of the window 172,and may or may not be provided.

The scale 168 of the illustrated embodiment is an index scale, whichprovides a relative indication of outlet pressure. Thus, each range ofthe index scale 168 may correspond to a predetermined value, or a rangeof values, for the fluid outlet pressure. Alternatively, the scale 168may provide actual fluid pressure outlet values.

In an alternative arrangement, the scale 168 may be provided on the cap150 and the reference indicia 170 may be located on the retainer 25′, orpossibly the base 15′. In this arrangement, the reference indicia 170may comprise a projection and/or colored region of the retainer 25′ orbase 15′. Of course, other suitable arrangements for indicating a valueon a scale may also be used. As such, it is not intended for theindicator arrangement 166 to be limited simply to the embodimentsdisclosed herein, but to include other suitable variations.

FIGS. 5-7 illustrate an alternative arrangement of the catch mechanism158. In this embodiment, the recesses 160 are defined on an upperannular surface of the retainer 25′ and the flexible tab 162 iscorrespondingly located on an upper surface of the cover 150. Inaddition, the recesses 160 are generally triangular in cross-section, asviewed in FIG. 5, with the radially innermost wall portion being rounded(FIG. 6). With reference to FIG. 7, the projection 164 issemi-cylindrical in shape. Otherwise, the embodiment of FIGS. 5-7 issimilar in construction and function to the embodiment describedimmediately above.

Although this invention has been described in terms of certainembodiments, other embodiments apparent to those of ordinary skill inthe art are also within the scope of this invention. Thus, variouschanges and modifications may be made without departing from the spiritand scope of the invention. Accordingly, the scope of the invention isintended to be defined only by the claims that follow.

1. A variable pressure regulator, comprising: a valve body having afluid inlet, a fluid outlet, a fluid pressure-sensing chamber; aresilient member comprising a wail section forming a wall of saidchamber, a periphery of said wall section secured to said valve body,said resilient member additionally comprising a valve stem connected tosaid wail section and extending through said chamber towards said fluidinlet, and a valve element supported on said valve stem and configuredto selectively close said fluid inlet; an adjuster assembly comprisingan adjuster member and a cover, said adjuster member movable relative tosaid valve body to deflect a portion of said wall section of saidresilient member, wherein said deflected portion is responsive topressure in said chamber to control a position of said valve elementwith respect to said fluid inlet, said cover being manually rotatablerelative to said valve body and configured to rotate said adjustertherewith such that a position of said deflected portion is capable ofbeing adjusted by rotation of said cover.
 2. The pressure regulator ofclaim 1, additionally comprising a detent mechanism defining a pluralityof angular positions relative to said valve body, said detent mechanismbeing configured to position said cover in one of said plurality ofangular positions and provide a force tending to inhibit unintendedmovement from said one of said plurality of angular positions.
 3. Thepressure regulator of claim 2, wherein said detent mechanism comprises aplurality of recesses defined by one of said valve body and said cover,and at least one projection fixed in relation to the other of said valvebody and said cover, said at least one projection configured to engageone of said plurality of recesses.
 4. The pressure regulator of claim 1,additionally comprising an indicator arrangement configured to relate anangular position of said cover to a position of said deflected portionof said resilient member.
 5. The pressure regulator of claim 4, wherein,said indicator arrangement comprises a fluid outlet pressure scale onone of said valve body and said cover, and a reference indicia on theother of said valve body and said cover, said reference indicia capableof being aligned with a demarcation of said fluid outlet pressure scaleto achieve a desired position of said deflected portion of saidresilient member.
 6. The pressure regulator of claim 2, additionallycomprising an indicator arrangement configured to relate an angularposition of said cover to a position of said deflected portion of saidresilient member.
 7. The pressure regulator of claim 6, wherein saidindicator arrangement comprises a fluid outlet pressure scale on one ofsaid valve body and said cover, and a reference indicia on the other ofsaid valve body and said cover, said reference indicia capable of beingaligned with a demarcation of said fluid outlet pressure scale toachieve a desired position of said deflected portion of said resilientmember.
 8. A variable pressure regulator, comprising: a valve bodyhaving a fluid inlet, a fluid outlet, a fluid pressure-sensing chamber;a resilient member comprising a wall section forming a wall of saidchamber, a periphery of said wall section secured to said valve body,said resilient member additionally comprising a valve stem connected tosaid wail section and extending through said chamber towards said fluidinlet, and a valve element supported on said valve stem and configuredto selectively close said fluid inlet; an adjuster manually movablerelative to said valve body to deflect a portion of said wall section ofsaid resilient member, wherein said deflected portion is responsive topressure in said chamber to control a position of said valve elementwith respect to said fluid inlet; a detent mechanism defining aplurality of relative positions between said adjuster and said valvebody, said detent mechanism being configured to position said cover inone of said plurality of relative positions and provide a force tendingto inhibit unintended movement from said one of said plurality ofrelative positions.
 9. The pressure regulator of claim 8, wherein saidplurality of relative positions between said adjuster and said valvebody are a plurality of angular positions.
 10. A variable pressureregulator, comprising: a base having a wall forming a wall of a fluidpressure-sensing chamber, said base further including a fluid inletopening to the chamber, and a fluid outlet in communication with saidchamber; a resilient diaphragm forming a wall of said chamber andcomprising a valve element mounted to a central section of saiddiaphragm and cooperating with said fluid inlet to selectively closesaid fluid inlet; a retainer secureable to said base configured to clampa peripheral portion of said diaphragm between the base and theretainer; an adjuster movable relative to said retainer and having aflange which engages a portion of said diaphragm, including said centralsection, so as to deflect said portion of said diaphragm towards thefluid inlet, said deflected portion of said diaphragrm being movable inresponse to fluid pressure within said chamber; a cover configured formanual movement relative to said base and said retainer, said coverconfigured to move said adjuster in an axial direction along with saidmanual movement of maid cover to adjust an axial position of saidportion of said resilient diaphragm; and a visual indicator to visuallyreflect to a user a current axial position of said adjustercorresponding to a current position of said cover.
 11. The pressureregulator of claim 10, additionally comprising a catch mechanismdefining a plurality of angular positions relative to said retainer,said catch mechanism being configured to position said cover in one ofsaid plurality of angular positions.